1.The D/L method was created by two English statisticians, Frank Duckworth and Tony Lewis, originating from an undergraduate final-year project at the University of the West of England.
2.It was first used in international cricket in the second game of the 1996/7 Zimbabwe versus England One Day International series, which Zimbabwe won by 7 runs,and was formally adopted by the International Cricket Council in 2001 as the standard method of calculating target scores in rain shortened one-day matches.
3.In the sport of cricket, the Duckworth-Lewis method (D/L method) is a mathematical way to calculate the target score for the team batting second in a one-day cricket or Twenty-20 cricket match interrupted by weather or other circumstanceThe Duckworth-Lewis method is used to help decide rain-interrupted one-day cricket matches.
3.It is named after Frank Duckworth and Tony Lewis who devised the mathematical formula.
4.HOW DOES IT WORK?
For example: a team have lost five wickets after receiving 25 of their 50 overs when rain stops play.
At this point, using the table produced by the Duckworth-Lewis method, the team’s remaining resources are valued at 42.2%.
If 15 overs are then lost because of the weather, the innings will be completed after only 10 more overs.
The D/L method says that, with 10 overs left and five wickets lost, the team has 26.1% of their resources left.
To compensate for the lost overs, we must calculate the resource % lost.
This works out to 42.2 – 26.1 = 16.1.
If the team had been chasing a total of 250 runs, their new target is calculated in the following way.
Resources available at the start = 100%
Resources lost = 16.1
Resources available after rain interruption = 83.9%
Then reduce team one’s score in the following way. Multiply team one’s runs scored by the recalculated resources divided by the resources available at the start.
That is: 250 x 83.9/100 = 209.75.
The target is then rounded to the nearest whole number, so the team batting second would be set a target of 210 to win.
5.Applied to 50 over matches, each team has to face at least 20 overs before D/L can decide the game. In Twenty20 games, each side has to face at least 5 overs.
6.An Example -
The “best-scoring overs” method, used in the 1992 Cricket World Cup, left the South African cricket team requiring 21 runs from one ball (when the maximum score from any one ball is generally six runs). Prior to a brief rain interruption, South Africa was chasing a target of 22 runs from 13 balls – which was difficult but at least attainable